Wanted to dump the waste gate back in the down pipe rather than in the air so it will be quite. I rode in a buddies car and when it starts to dump it is so loud and every one knows what is going on under that hood at that point. So no stealth mode when it dumps in the air but dont want it sapping a bunch of power either. Anyone have experience with this. Maybe had it in air then put it in the pipe and it changed. I think the car will make more power than I need and it wont matter either way but just thought I should ask before welding it in.

 

How big of down pipe are you running? To be honest you will loose some power. How much is hard to say. Not exactly the same but when I put an external wastegate on my wrx I gained 20whp.

 

3 inch down pipe. I am going to be conservative with the setup and keep it under 650whp as my bottom end wouldnt like more than that for very long. I have a t-76 cbb that is good for 25+lbs and dont plan on much over 12 to see around the 650 mark. afr heads and cam on a 383 should acheive that pretty easy so I guess if I have to add a pound to make up for it then so be it as I want it quite when under boost.

 

I think you'd be fine. 3" on a single turbo for a sbc is a little small but i Know room is tight with out alot of work.
I run a 5" dp on my V6 car 86 Camaro. But it wasn't easy.
All GN's are internal dump. External or interal gate unless the owner made it a external dump which I've never seen on anything but a race car.
I'm all for quiet and stealth. Keep it internal and put another lb of boost in it
~Scott

 

Yeah sounds good to me. Once I get the 3 inch in place and drive it and get it all tuned I might try to go bigger on the downpipe in the future. Right now just wanna get it going and will make it bigger if need be. My friend made 750rwhp on his 356 inch ford in a mustang with a t-76 on 15lbs . Here is what I cant believe. It has a 1 and 3/4 cross over pipe. TINY!!!! and other connecting pipe is 2 inch. the down pipe on it is also 3 inch. I cant believe that small pipe set up makes that much power. I used 2.5 for my crossover and at one point to clear the pitman arm went down to 2.25 so it would leave room to the heater hose and still turn all the way.So expect this combo to have to be tuned back to not go over the 650rwhp I am looking for.